A motor-vehicle door latch typically comprises a bolt attached to and extending perpendicularly from the doorpost and a latch on the door edge. The latch has a pivotal fork that engages around the bolt to secure the door tightly in place. The bolt is typically part of an assembly comprised of a metallic U-shaped yoke having an inner flange adapted to be secured to the doorpost and an outer flange spaced therefrom, forming a fork-receiving space therewith, and having an outer surface turned away from the inner flange. The bolt is also metallic and is fixed to the two flanges so as to extend generally perpendicularly therebetween.
It is standard to provide at each door a switch which is actuated when the respective door is closed to signal to an on-board control system the condition of the door. Thus if a door is not fully closed a lamp on the dashboard will light to warn the driver of this potentially dangerous condition.
As a rule a simple pushbutton switch is employed which is opened when engaged by a flange of the door. It is normally necessary for the door to be fully closed in order for its edge flange to actuate the switch, normally by depressing the button of the switch which projects outward and horizontally in the direction the door moves in when closing.
The problem with this arrangement is that the switch is subjected to considerable physical shocks as the door is closed. In addition it is in a relatively exposed position on the door post. The result is a reduced service life for this switch.